1. Technical Field
The disclosure relates to an input apparatus, and more particularly to a non-contact input apparatus for computer peripheral and method of the same.
2. Related Art
Currently, a digital board is used with a wireless pointer. When a wireless pointer contacts a digital board, the wireless pointer will generate an electromagnetic induction signal. In such a way, the digital board may utilize magnetic coupling to calculate the coordinates of the wireless pointer and then send the coordinates to the computer.
In order to avoid the inconvenience of using batteries, the power source supply needed by the wireless pointer can be obtained by electromagnetic resonance. After receiving the electromagnetic resonance signal, the wireless pointer converts the electromagnetic resonance signal to be the electromagnetic induction signal.
In the prior art, the wireless pointer comprises two different coils, one of which is used to receive the electromagnetic resonance signal, and the other of which is used to transmit the electromagnetic induction signal. FIG. 1 shows a prior art circuitry of a wireless pointer. The wireless pointer comprises a receiving module 70, a conversion module 80, and a transmitting module 90. Furthermore, the receiving module 70 comprises a first coil 72, a first capacitor 73, a second capacitor 74, a third capacitor 75, a fourth capacitor 76, a fifth capacitor 77, and a Zener diode 78. The conversion 80 comprises a filter 82 and a DC to DC converter 84. The transmitting module 90 comprises a first resistance 911, a second resistance 912, a third resistance 913, a fourth resistance 914, a sixth capacitor 921, a seventh capacitor 922, a eighth capacitor 923, a ninth capacitor 924, a tenth capacitor 925, a eleventh capacitor 926, a twelfth capacitor 927, a thirteenth capacitor 928, a fourteenth capacitor 929, a fifteenth capacitor 930, a second coil 941, a third coil 942, and a first diode 951.
The first coil 72 is used to receive the electromagnetic resonance signal. The second coil 941 and the third coil 942 are used to transmit the electromagnetic induction signal. Accordingly, the prior art wireless pointer has too many elements. The more elements there are, the higher the manufacture cost of the wireless pointer will be. Although the above mentioned capacitors can be replaced by a capacitor with a greater capacitance, the capacitor with a greater capacitance usually requires a greater amount of room which results in a big wireless pointer.